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MEP-803A flywheel issue

BrnH2ORat

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I've seen all the bolts shear before, but more commonly the drive plate is what gives up the ghost. You might want to have it magnafluxed to confirm no hairline cracks before reassembly.
My guess is the bolts never were torqued correctly, it only has a few hours on it after coming out of depot for the tier II upgrade, Yep, magnafluxing both the drive plate hub and flywheel and crankshaft end is probably a good idea, I'll throw them on the bench in the morning and sprinkle some magic dust on them and hopefully wont find any cracks !
 

BrnH2ORat

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None of them have the dowel pin hole.

As far as I remember, 10.9 was what its supposed to be.
I think Monday I'm going to contact Lister and or Onan and see why they don't use a dowel pin in the flywheel ? It wouldn't be to hard to put the flywheel on my milling machine and drill out a dowel hole BUT there is a reason MAYBE that this isn't done at the factory. might be a designed weak link to protect the crankshaft.
I'm also questioning if these are the correct bolts being used. They look like home depot off the shelf cheap Chinese bolts, not something that meets MILSPEC, I did find the NSN for these, 5305-01-368-7450 but haven't found the MILSPEC info for the bolt.
 

Ray70

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Well I guess I'll know in a few days! I'm in the middle of doing the machine work on a Perkins 1104C, making 1 good engine from 3 bad ones. I'll have to figure out if this DN4M has stock crank journals, don't want to replace rods if I don't have to.

I see here where we went off track on the rods... It really sounded like you were not looking forward to changing rods on the DN4M in your 803, not the 1104C Perkins.... guess that post got a little mixed up!
 

BrnH2ORat

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I wasn't looking forward to changing rods in either! I didn't want to have to pull out and taredown the 803, I've already got 3, 1104's tore down and piles of parts all over.

I did find out the 803 has had the rods and crank and bore machined, 10 thousands under on crank & rods, 10 over on the bore.
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BrnH2ORat

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I've got a handful of parts engines here if you need bolts, FYI.
Would you be able to post a picture of the bolts? and a length measurement? I have a really good industrial hardware supplier near me who stocks a lot of good quality metric hardware, I searched all over for the MILSPEC for them, it would give all the dimensions but had no luck on that.
 

BrnH2ORat

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Broke one apart today. See below. Sorry I don't have a thread gauge handy, but you should be able to pick up pitch and thread count off your remnants? Metric conversion on your time not mine ;)

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Thanks for the pic's I just actually received in the mail a package with a new crankcase door gasket, factory flywheel bolts and a new dowel pin from Gary Jones of Diesel Electric Service in Kansas who as I understand it bought out the entire Lister Petter manufacturing plant when they closed down, seemed to know the LPW4 engine and the MEP800's inside and out. The flywheel does indeed have a dowel pin, Gary said that when they sheer it's such a clean break that you can't even see where it was at, said it very common. Well I went out and wire wheeled the flywheel flange and used a magnifying glass and yep, he was right! I magnafluxed it and it stood out like a sore thumb! he sent me a picture of a new flywheel and it has the hole for the pin. it is a press/interference fit, said to find the rough center and use a punch to knock it out the back. mine didn't want to budge so I drilled out the center and then punched it out!
 

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Light in the Dark

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As knowledgeable as Gary is on the L-P products, I don't believe he is correct here. I am siding with Guy. Here are some photos of the unit I just took apart. The unit I broke down was factory tight, no sign of shear on the 'pin'. There is a hole on the flywheel, and it does appear to be filled in stock. No sign of breakage or other destructive forces. You can tell because the factory face finish grooving on the inner mounting face of the flywheel, perfectly carries over the 'pin'.

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BrnH2ORat

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Missouri
As knowledgeable as Gary is on the L-P products, I don't believe he is correct here. I am siding with Guy. Here are some photos of the unit I just took apart. The unit I broke down was factory tight, no sign of shear on the 'pin'. There is a hole on the flywheel, and it does appear to be filled in stock. No sign of breakage or other destructive forces. You can tell because the factory face finish grooving on the inner mounting face of the flywheel, perfectly carries over the 'pin'.

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I agree, mine was the same, no pin in the crankshaft side. The LPW4 parts book lists the generator flywheel part number and also lists the part number for the dowel pin, no note on the flywheel about leaving out the pin. I wonder what the difference is between the commercial Lister/Onan genset setup vs the MEP803 setup?
 

Light in the Dark

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The flywheel in the 803a is special for the application (and will not work with a 12v starter). I assume the flywheel was designed to a print of the LP crank, and it was later decided that no pin would be used... And this was somehow an easier option than changing the print? Who knows... There are reasons why Lister went bankrupt so many times.
 

BrnH2ORat

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Missouri
The flywheel in the 803a is special for the application (and will not work with a 12v starter). I assume the flywheel was designed to a print of the LP crank, and it was later decided that no pin would be used... And this was somehow an easier option than changing the print? Who knows... There are reasons why Lister went bankrupt so many times.
Well one thing I realized after 27 years in the military that there's the right way, the wrong way and the government way.
 

BrnH2ORat

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Thank you everyone for all the input and information, I received all my parts so I'm going to put this thing back together and see if it makes reliable power. I'm in the process of building a new house farther back on my property, just poured the foundation and my local electricity co-op just got the power vault and transformer set, I plan on pouring a small slab and setting up a transfer switch to use it as a backup system.
 
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